The engine started to misfire at times. After a cool-down it would again operate OK. The check engine light would illuminate. Checked with an OBII tester and it indicated a misfie on #3 cylinder. Pulled the coils from #2 & #3 cylinders. Checked them with an ohmmeter. #2 had radically different reading than #2. Got a new coil for #3 cylinder. Everything now seems OK.